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Skinny on the Cam chain guard

114K views 247 replies 57 participants last post by  DougM 
#1 ·
Ok so the newer style tensioner is old news by now, so if ya haven't yet its time to get that done, both old and new are hydrolic but the new has holes in the mounting plate and the cap that bolts where the old plate did acts as a reservior. The deal with the "chaintooth jump guard", is pretty simple, remove clutch/crankend cover and it snaps into place over the existing guard casted into the case then held in place with the cover, adding additional protection to keep the chain from skipping a tooth should something cause it to. I should have done all of this myself, but the other day on the phone with the dealer this was new as of last month and the service bulletin was not all that clear as to what held the guard in place so I opted to pay and watch this time, education comes with a tuition price and this one was about two and a half hrs. shop time on the first go, but its only about an hour and a half job, this guy is a clean freak, after finishing he was back there with a can of cleaner in one hand and a fresh micro-fiber cloth in the other removeing any trace he'd been there. They did it on saturday, a good job while I waited so I paid cash and thanked them. The parts, gastet, tensioner kit, guard and one time screws etc. run about two bills plus labor, 400 dallars for the peace of mind that I've done all that can be to this point to prevent cam chain/related failures.
 
#78 ·
I'm still wondering about the 18 bolts needed and if they really need to be replaced?

Reason being that on their S1000RR engine, there are many aftermarket case savers for the left and right side to protect the engine in the event of a fall over or slide on the track and they simply "reuse" those engine bolts for the covers on both sides. No one mentions buying new bolts for those engines (I haven't checked the BMW RepROM DVD on it to see if they recommend replacing those either, but they might.).

Even the oil-heads reuse their bolts on their cylinder covers (BMW used to always say you needed a new valve cover gasket each time you got in there to do the valves too, but many just reused the rubber thing over and over again. I did too and never had a leak.).

I guess you could measure an old bolt length vs. a new one and see. :confused:


Mack
 
#79 ·
GMack said:
I guess you could measure an old bolt length vs. a new one and see.
Out of curiosity I did just that. The used bolt was about 0.5 mm longer than the new, probably too small an amount to prove anything one way or the other, maybe just a difference of manufacturing tolerance.

In this case the bolts are made of aluminum so that is probably the difference between these and the items you mentioned above. Truth be told I don't know if the world would end if you were to re-use the bolts, since there are 18 and spaced closely together you could probably just torque them to 5 nm (what is speced for the clutch slave cylinder that uses the same bolts) and probably not have any leaks or issues. But what can I say, the all-caps warning in the manual to not re-use the old bolts got to me, plus as I mentioned in my earlier post the aluminum bolts sure did feel weird when I tightened them so I was glad I was not experimenting. But if you were in a jungle somewhere and didn't have new bolts I think you could probably re-use the originals if you were careful.
 
#82 ·
I just checked the BMW service ROM for the S1000RRR and they also say to "Install new screws" (M6x35) as well - although it seems no one is doing it with the case covers the dealers are selling. The torque values on it are 3Nm (or 2.2 lb-ft) and 90 degrees. Doesn't seem like enough to damage or stress a M6 bolt. Dunno.

Mack
 
#85 ·
So I read through all nine pages about this issue. Did we ever answer the question if all the K13GTs where affected? Or did I miss it? Mine is a new 2010 with about 2500 miles. I still have the stock tires for Christ sakes! Is this something the dealer should address or just spent the $100 bucks and fix it myself? Seems retarded to have to fix a perfectly good motorcycle. :banghead:
 
#86 ·
Randog said:
Did we ever answer the question if all the K13GTs where affected?
I don't think anyone knows for sure. There have been more 1200's affected but that could be due to higher average age/mileage. I'm not sure if I've heard of a 1300 that has had a top-end blow up (yet) but the design is essentially the same so there's no reason that the 1300 should be immune, or at least no reason we know of. So bottom line... your guess is as good as anyone's...
 
#87 ·
Affected how? Do you have to have the part? No. Should you? Well.....

The logical answer is that both the 12 and 13's are essentially the same exact design as far as the cam chain assembly is concerned. The 13's have the new tensioner but they do not have the jump guard. It was made to fit both bikes for a reason. Me thinks that the prudent thing to do would be install it. How ever there will always be those that think I / some of us are over reacting and that their bikes are immune or that there's no real issue or that it's a minor percentage of the total and no need for a fix etc etc.

Funny how time brings clarity. Gosh, now there are multiple fixes for an issue that was supposedly non existent!

Your bike, your choice.
 
#88 ·
Robert_W said:
Me thinks that the prudent thing to do would be install it.
I agree. As I said earlier the odds of any given bike blowing up may be small, but the cost of the fix is too low and the potential consequences (if you are one of the unlucky ones) too high to pass it by, IMO. And that would go for any slant-K bike, 1200 or 1300.
 
#89 ·
Since this "Magic Piece" only became known around Nov. 2010, I would expect all K1300's to be without it. Maybe beginning with the 2011 engine builds which might have it - if they are making any more 1300 sized engines in 2011.

Personally, I'd look to getting it installed - and pronto! Time waiting for a warranty fix can take forever (weeks/months) if you are 500-1,000 miles from home and the engine suddenly blows chunks. Not that mine has ever done something like blowing engine chunks (yet), rather it just wants to stop running or self-crash (i.e. vandalism) and cut the clutch line - and a long ways from home too. Least you get to visit a lot of different service shops though.

Rental car was nice, and it verified that the "Liquid tire balancing & flat fixer stuff" I put in my own car's tires was crap since mine hammered driving down the road and also got a flat due to a 1/4" lag bolt that defied the stuff's flat-fixing capabilities. Least I carry one of those dart-firing 'Stop and Go' pluggers that seems to work well with the liquid stuff, aside from the being off-balance with the liquid. Probably a half dozen darts in the car tires now. Damn construction trucks seem to drop all sorts of debris on the road near home fix-it centers and I find it, even on the GT (which gets their condensed ''S&G' plugger and a small 12 volt compressor in one side bag).


Mack
 
#90 ·
Robert_W said:
No way...plastic? Seriously? :confused: Like the same stuff that the guides are made of? Wow. Not instilling a whole lot O' confidence. :wtf: But par for the course I guess! :D

I'm still waiting on back order screws. Should have ordered from Max's I guess.



Actually, plastic is an ideal material for this use. I'm quite confident the choice for plastic had less to do with economics and more to do with scope.
 
#91 ·
eng943 said:
Actually, plastic is an ideal material for this use. I'm quite confident the choice for plastic had less to do with economics and more to do with scope.
Yes I suppose this is true. Some of the nylons and plastics nowadays would work quite well. Very tough yet slippery at the same time.

Funny how the mind thinks old school. Brought up on metal being tough and strong. Just seems strange...plastic....in an engine. Better...stronger....faster. As a kid I had the 6 Million Dollar Man......now I got the 6 Dollar Part. Humph. :loco

On a positive note I just got an email that my parts actually shipped today. Woohoo! Look out warm weather.....road trip time. :clap: :yeah:
 
#93 ·
Robert_W said:
Yes I suppose this is true. Some of the nylons and plastics nowadays would work quite well. Very tough yet slippery at the same time.

Funny how the mind thinks old school. Brought up on metal being tough and strong. Just seems strange...plastic....in an engine. Better...stronger....faster. As a kid I had the 6 Million Dollar Man......now I got the 6 Dollar Part. Humph. :loco

On a positive note I just got an email that my parts actually shipped today. Woohoo! Look out warm weather.....road trip time. :clap: :yeah:
If I weren't an engineering geek, I probably would have had the same perception.
 
#94 ·
Randog said:
Seems retarded to have to fix a perfectly good motorcycle.
In theory I totally agree, but my years of BMW experience tells me it's better to just do the fix . . .

I definitely will be doing this upgrade myself. My '09 had one very hard and loud jerk once when starting, and all I could think of was pics of Robert's cratered valve train . . .

Hey Randog, since you're just down the road from me, I'd be glad to do your bike as well. I'm riding out of state for the next few weeks, but we can sort it out when I get back if you haven't gotten to it yet.

That goes for anyone else near L.A. as well. :)
 
#95 ·
Ken, sure would appreciate a nice write-up (with lots of pictures) from you or Robert when you tackle this seemingly easy install. Don't think it's even a question how this should end up in the Hall Of Wisdom.

Congrats BTW on your new K13GT. Hope you're liking it so far and have put at least 50 or so miles on the bike to date...

Ride safely!
 
#96 ·
Actually, I've put 2,500 miles and 6 states on it since Thursday . . . :D

I'm working in Plano for the next couple of weeks. If you can get the parts in, I'd be glad to give you a hand . . .
 
#97 ·
Meese said:
In theory I totally agree, but my years of BMW experience tells me it's better to just do the fix . . .

I definitely will be doing this upgrade myself. My '09 had one very hard and loud jerk once when starting, and all I could think of was pics of Robert's cratered valve train . . .

Hey Randog, since you're just down the road from me, I'd be glad to do your bike as well. I'm riding out of state for the next few weeks, but we can sort it out when I get back if you haven't gotten to it yet.

That goes for anyone else near L.A. as well. :)
Thanks for the offer Ken, I'm a fairly good gear head, got all the tools and a lift too, so I most likley will do it myself. I might although, take you up on watching you do it to your bike when you get back and pick your brain some. I work I Oxnard so I'm around every day during the week.

I'm off myself for our anual Death Valley April Fools Day ride on the 1st so I wouldn't even get around to ordering the parts until after I get back. I like the idea of changing out the bolts to SS although.

I'm not so sure that BMW shouldn't be taking care of this for us, especialy since mine is still under warranty. I need to call down to the local shop tomarrow and find out the scoop.

Plano, Tx? Have a nice trip..
 
#99 ·
kbmwrs said:
The CAM chain guard is not a warranty item so I doubt if BMW will do anything.

On the other hand if you have an extended warranty a case can be made that not doing it would cause a major engine failure which would cost the warranty service even more.
kbmws is right, I called the dealer and the Chain tooth Jump Guard is not a warranty item nor is it part of a recall at this time. My 2010 13GT did not have one installed in it but the 2010 13GT does have the newer style Tensioner. Although he has never seen a GT (1200 or 1300) with chain that has jumped with a older style tensioner, the older style tensioner should considered being replaced at some point when out of specification. The guard would be installed as an extra piece of mind.

I got sucked into a similar situation on my Harley. There was a lot of hype going around on the internet forums about the timing chain coming off because of the manual tesioner on the touring bikes. I bought into it and after about $200 and a day of my labor I had changed mine out to the new auto tensioner. I didn’t need to do it; it appears that this one guy, while racing his Harley spun the chain because it was out of adjustment and because of his lack of maintenance it became this hairy hyped out internet issue.

I’m wiser now and I personally doubt that plastic guard will minimize the damage done by a timing chain coming off at high RPMs. I would if I had the older style tensioner would maintain the chain tension per the recommended specifications and replace if it was out.
 
#100 ·
Randog said:
I’m wiser now and I personally doubt that plastic guard will minimize the damage done by a timing chain coming off at high RPMs. I would if I had the older style tensioner would maintain the chain tension per the recommended specifications and replace if it was out.

I don't think the plastic chain guard is meant to protect anything if the chain comes off or breaks. My guess is that it is there merely to prevent the chain from 'jumping' off there at the small sprocket is enough slack exists.
 
#101 ·
kbmwrs said:
I don't think the plastic chain guard is meant to protect anything if the chain comes off or breaks. My guess is that it is there merely to prevent the chain from 'jumping' off there at the small sprocket is enough slack exists.

And that is all it is made to do just like the ones on my ricers. The chains will not jump off the cams on the ricer because of a guard with a plastic slider that goes between the cams and the crank gear has the guard to keep the chain from jumping a tooth. Cannot move the chain on the crank without taking the guard off.
Chain could get real sloppy and hopefully stay in time but if it snaps or a cam gear comes off then it will not be pretty.

I do not know how beemer is with cam gears but I do know I am not the kindest person on my 2009 13GT
 
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